This document provides step-by-step instructions for setting up a standalone Cisco Unified Communications Manager Express (CME) that uses SIP phones. The document outlines a Cisco Unified Communications Manager Express system with four SIP phones, with configurations for setting up the Cisco Unified Communications Manager Express system and SIP phones.

Note: 3911 and 3951 phones use the same firmware, so you need not be concerned that the filename reflects a 3951 phone.

After you have unzipped both the ZIP files in your TFTP folder, copy all the firmware files onto the Cisco Unified Communications Manager Express flash with your TFTP server. Make sure you copy all these files onto flash.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Configure DHCP

It is necessary to configure two separate DHCP pools; IP Phones use the Voice DHCP pool and PCs use the Data DHCP pool. IP Phones need to use DHCP option 150 in order to provide the IP address of the TFTP Server.

If there are any devices in either pool with static IP addresses, make sure these addresses are excluded from the DHCP pool in order to avoid addressing conflicts. You can use the show ip dhcp binding command in order to verify which addresses the IP Phones and PCs receive from the router.

Configure the switchports to be connected to both the Voice and Data VLANs. IP Phones are automatically assigned into the Voice VLAN and PCs connected to either the switchport directly or connected to the switchport on the IP Phone that is assigned to the Data VLAN.

Configure connection to Cisco Unity Express

Configure necessary dial-peers and MWI ephone-dns to interoperate with Cisco Unity Express. In order for Cisco Unified Communications Manager Express to interoperate with Cisco Unity Express, it is necessary to configure SIP Cisco Unified Communications Manager Express as a back to back user agent (B2BUA), which means that all the signaling and RTP stream goes through the Cisco Unified Communications Manager Express. This configuration is required in order to enable connectivity to Cisco Unity Express.

Note: Multiple methods for DTMF can be configured under voice register pool, but for each SIP phone that has a voicemail box on Cisco Unity Express, configure dtmf-relay sip-notify.

Configure advanced parameters

In this section, you configure advanced parameters for SIP phones such as presence with Busy Lamp Field (BLF) status. Presence with BLF allows either a SCCP phone or SIP phone to monitor the status of another SIP extensions, which enables presence information between phones.

Note: This is an optional configuration.

These phones support SIP presence service on Cisco Unified Communications Manager Express.

Complete these steps in order to enable a line associated with a directory number to be monitored by a phone registered to a Cisco Unified Communications Express router. The line is enabled as a presentity and phones can subscribe to its line status through BLF call-list and BLG speed-dial features. There is no restriction on the type of phone that can have its lines monitored; any line on any IP phone or on an analog phone on supported voice gateways can be a presentity.

voice register dn 1
number 101
allow watch
!--- Allow this number to be watched.
name Phone1
label 4085251001

Note: Repeat this configuration for each extension number that needs to be watched. This step was already done when you first configured voice register dns.

Enable the SIP Phone to Monitor BLF Status for Speed-Dials and Call Lists

A watcher can monitor the status of lines associated with internal and external directory numbers (presentities) through the BLF speed-dial and BLF call-list presence features. Complete these steps in order to enable the BLF notification features on a SIP phone:

A common cause for SIP IP Phones that are not able to get a dial tone is that there is another phone with the same extension. As of Cisco Unified Communications Manager Express 4.2, shared line is not supported on SIP Phones. Thus, SIP phones can not share the same extension among multiple phones. Additionally, make sure that the SIP phone is provisioned with a proper extension.

In order to resolve this issue, make sure that these occur:

The SIP phone has the extension configured and extension shows on SIP phone.

There is not another SIP or SCCP phone configured with the same extension.